Would you be so kind to tell us a bit more about your experience. I've heard and read all great things about the software, MSO. I tried and it seems a lot of work and overly complicated.
Peace
I'd be happy to help. It's not complicated, but it is a lot of effort. There are just a lot of things that need to be accommodated in your project:
Part 1: Configuration
- subwoofer channels
- each subwoofer's available EQ adjustments
- gain
- delay
- polarity inversion
- parametric EQ (which includes low/high shelf)
- count of available parametric EQ
- adjustability of each parametric (for example, max Q)
- all-pass filter
The permutations must be created within your project. You can duplicate channels and filters which helps if all of your EQ and subwoofers are identical. The project would look something like this:
- channel 1
- gain block
- delay block
- PEQ1
- PEQ2
- ...
- channel 2
- gain block
- delay block
- PEQ1
- PEQ2
- ...
- ...
You can get by with as little as 1 or 2 PEQ filters per channel. I'd recommend 4. You can do more later, but increasing the count of filters will increase your computational complexity (and efficiency) exponentially. With lots of channels and lots of filters, sufficient optimization will take at least several hours. More listening positions also factors in (exponentially).
Part 2: Measurements
You have to determine which positions to take measurements at. You could spread these out around your listening area. You can weight which positions matter more, too. What's important is you have individual measurements for each channel in your setup and each individual measurement position. 5 seats and 4 subwoofer channels = 20 measurements. You'd want to be reasonably fluent with REW to do this. It's also important you have a consistent timing reference. Subwoofers will not produce a sweep that allows for time alignment. I used my left stereo channel to accomplish this, but I also had to quickly turn off said left stereo channel after the timing sweep or else it would interfere with my sub channel measurement. It was very tedious.
These measurements are imported into MSO. You should take care to be precise with your measurement file names, to correctly associate positions and channels.
Part 3: Calculation
This can take several hours of CPU time. MSO optimizes each channel's available adjustment filters. There are optimization parameter limits you can use, such as max delay, or minimum gain. The first few minutes are fun to watch, as MSO shows a real time approximation of what your system response will be, vs. the measurements. It gets closer and closer, and sometimes changes completely as the optimizer finds a novel optimization branch. In case it's not obvious, this program does not have a closed-form algebraic solution that it is calculating. It has an open-form, non-deterministic strategy (
Nondeterministic algorithm - Wikipedia ).
Part 4: Integration
At this point MSO would tell you the best filters to use for every channel. It will even show you the combined response and what to expect (which measurements will later confirm to be remarkably prescient). There are many system topologies that could determine how you accomplish this - whether you are also using Dirac, whether you can adjust a house curve before or after the subwoofer channel's PEQ filters, whether you can high pass your stereo channels, whether you can low pass the 'mid' EQ section that would be just your subwoofer's EQ channels altogether, desired crossover between subs and mains, etc. There are too many possibilities to enumerate here.
Hope this helps. Happy to help with more if you have specific questions. The sum total of all this work is a bass frequency response that is simply unbelievable.
(j/k)
